#include "sd.h"
#include "sd_io.h"
#include <sys/unistd.h>
#include <sys/stat.h>
#include <string.h>
#include "esp_vfs_fat.h"
#include "sdmmc_cmd.h"
#include "driver/sdmmc_host.h"

#define MOUNT_POINT "/sd"

static const char *TAG = "SD_CARD";

#define CONFIG_PIN_CMD 1
#define CONFIG_PIN_CLK 2
#define CONFIG_PIN_D0 3
#define MAX_CHAR_SIZE 64

void sd_init(esp_io_expander_handle_t io_expander)
{
    ESP_LOGI(TAG, "Initializing SD card");
    esp_io_expander_set_dir(io_expander, IO_EXPANDER_PIN_NUM_7, IO_EXPANDER_OUTPUT);
    esp_io_expander_set_level(io_expander, IO_EXPANDER_PIN_NUM_7, 0);

    vTaskDelay(pdMS_TO_TICKS(200));
    esp_io_expander_set_level(io_expander, IO_EXPANDER_PIN_NUM_7, 1);

    esp_err_t ret;

    // Options for mounting the filesystem.
    // If format_if_mount_failed is set to true, SD card will be partitioned and
    // formatted in case when mounting fails.
    esp_vfs_fat_sdmmc_mount_config_t mount_config = {
        #ifdef CONFIG_EXAMPLE_FORMAT_IF_MOUNT_FAILED
                .format_if_mount_failed = true,
        #else
                .format_if_mount_failed = false,
        #endif // EXAMPLE_FORMAT_IF_MOUNT_FAILED
                .max_files = 5,
                .allocation_unit_size = 16 * 1024};
            sdmmc_card_t *card;
            const char mount_point[] = MOUNT_POINT;
            ESP_LOGI(TAG, "Initializing SD card");

            // Use settings defined above to initialize SD card and mount FAT filesystem.
            // Note: esp_vfs_fat_sdmmc/sdspi_mount is all-in-one convenience functions.
            // Please check its source code and implement error recovery when developing
            // production applications.

            ESP_LOGI(TAG, "Using SDMMC peripheral");

            // By default, SD card frequency is initialized to SDMMC_FREQ_DEFAULT (20MHz)
            // For setting a specific frequency, use host.max_freq_khz (range 400kHz - 40MHz for SDMMC)
            // Example: for fixed frequency of 10MHz, use host.max_freq_khz = 10000;
            sdmmc_host_t host = SDMMC_HOST_DEFAULT();

            // For SoCs where the SD power can be supplied both via an internal or external (e.g. on-board LDO) power supply.
            // When using specific IO pins (which can be used for ultra high-speed SDMMC) to connect to the SD card
            // and the internal LDO power supply, we need to initialize the power supply first.
        #if CONFIG_EXAMPLE_SD_PWR_CTRL_LDO_INTERNAL_IO
            sd_pwr_ctrl_ldo_config_t ldo_config = {
                .ldo_chan_id = CONFIG_EXAMPLE_SD_PWR_CTRL_LDO_IO_ID,
            };
            sd_pwr_ctrl_handle_t pwr_ctrl_handle = NULL;

            ret = sd_pwr_ctrl_new_on_chip_ldo(&ldo_config, &pwr_ctrl_handle);
            if (ret != ESP_OK)
            {
                ESP_LOGE(TAG, "Failed to create a new on-chip LDO power control driver");
                return;
            }
            host.pwr_ctrl_handle = pwr_ctrl_handle;
        #endif

            // This initializes the slot without card detect (CD) and write protect (WP) signals.
            // Modify slot_config.gpio_cd and slot_config.gpio_wp if your board has these signals.
            sdmmc_slot_config_t slot_config = SDMMC_SLOT_CONFIG_DEFAULT();

            // Set bus width to use:
        #ifdef CONFIG_EXAMPLE_SDMMC_BUS_WIDTH_4
            slot_config.width = 4;
        #else
            slot_config.width = 1;
        #endif

            // On chips where the GPIOs used for SD card can be configured, set them in
            // the slot_config structure:
        #ifdef CONFIG_SOC_SDMMC_USE_GPIO_MATRIX
            slot_config.clk = CONFIG_PIN_CLK;
            slot_config.cmd = CONFIG_PIN_CMD;
            slot_config.d0 = CONFIG_PIN_D0;
        #ifdef CONFIG_EXAMPLE_SDMMC_BUS_WIDTH_4
            slot_config.d1 = CONFIG_EXAMPLE_PIN_D1;
            slot_config.d2 = CONFIG_EXAMPLE_PIN_D2;
            slot_config.d3 = CONFIG_EXAMPLE_PIN_D3;
        #endif // CONFIG_EXAMPLE_SDMMC_BUS_WIDTH_4
        #endif // CONFIG_SOC_SDMMC_USE_GPIO_MATRIX

            // Enable internal pullups on enabled pins. The internal pullups
            // are insufficient however, please make sure 10k external pullups are
            // connected on the bus. This is for debug / example purpose only.
            slot_config.flags |= SDMMC_SLOT_FLAG_INTERNAL_PULLUP;

            ESP_LOGI(TAG, "Mounting filesystem");
            ret = esp_vfs_fat_sdmmc_mount(mount_point, &host, &slot_config, &mount_config, &card);

            if (ret != ESP_OK)
            {
                if (ret == ESP_FAIL)
                {
                    ESP_LOGE(TAG, "Failed to mount filesystem. "
                                  "If you want the card to be formatted, set the EXAMPLE_FORMAT_IF_MOUNT_FAILED menuconfig option.");
                }
                else
                {
                    ESP_LOGE(TAG, "Failed to initialize the card (%s). "
                                  "Make sure SD card lines have pull-up resistors in place.",
                             esp_err_to_name(ret));
        #ifdef CONFIG_EXAMPLE_DEBUG_PIN_CONNECTIONS
                    check_sd_card_pins(&config, pin_count);
        #endif
                }
                return;
            }
            ESP_LOGI(TAG, "Filesystem mounted");

            // Card has been initialized, print its properties
            sdmmc_card_print_info(stdout, card);
}

esp_err_t s_write_file(const char *path, char *data)
{
    ESP_LOGI(TAG, "Opening file %s", path);
    FILE *f = fopen(path, "w");
    if (f == NULL)
    {
        ESP_LOGE(TAG, "Failed to open file for writing");
        return ESP_FAIL;
    }
    fprintf(f, data);
    fclose(f);
    ESP_LOGI(TAG, "File written");

    return ESP_OK;
}

esp_err_t s_read_file(const char *path)
{
    ESP_LOGI(TAG, "Reading file %s", path);
    FILE *f = fopen(path, "r");
    if (f == NULL)
    {
        ESP_LOGE(TAG, "Failed to open file for reading");
        return ESP_FAIL;
    }
    char line[MAX_CHAR_SIZE];
    fgets(line, sizeof(line), f);
    fclose(f);

    // strip newline
    char *pos = strchr(line, '\n');
    if (pos)
    {
        *pos = '\0';
    }
    ESP_LOGI(TAG, "Read from file: '%s'", line);

    return ESP_OK;
}
